A cold, low-pressure system is freezing much of the United States. It's called a Polar Vortex, and as the name suggests, it usually hangs out around the North and South Poles. But this rotating mass of cold dense air is being pushed south from its usual place in northern Canada, sending temperatures plummeting. The Midwest bears most of the brunt, but as Arash Arabasadi reports, almost no one is being spared.
